Illuminated picture frame

ABSTRACT

A display apparatus comprising a frame adapted to engage and support the edges of a picture, a casing defining a cavity disposed behind the plane occupied by the picture in use of the apparatus, lighting device located in the cavity, a power source for the lighting device, wherein the lighting device comprising a linear array of light emitting diodes mounted in respective apertures in an elongate laminar support and arranged to provide backlit illumination for a picture located in the frame, the array being located in a tubular diffuser located in a light transmitting tube, the diffuser having a diameter less than the diameter of the tube, the tube being disposed axially of the casing; and wherein control circuitry and a battery compartment are enclosed by cover plates forming a channel to receive the lighting device.

RELATED APPLICATION

The present invention claims priority to U.S. Provisional ApplicationNo. 60/821,970 filed Aug. 10, 2006 and entitled “ILLUMINATED FRAMEAPPARATUS” and is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

Heretofore picture frames have not had adequate lighting. A need existsto provide for the same.

SUMMARY OF THE INVENTION

This invention relates to an illuminated picture frame of the kindwherein a picture, for example a photograph, drawing, painting, print orthe like, hereinafter referred to as a picture, is mounted with theedges engaged in a frame and with a lamp or light located behind thepicture to illuminate the image.

According to the present invention, a display apparatus comprises aframe adapted to engage and support the edges of a picture, a casingdefining a cavity disposed behind the plane occupied by the picture inuse of the apparatus, lighting means located in the cavity, a powersource for the lighting means, wherein

-   -   the lighting means comprising a linear array of light emitting        diodes mounted in respective apertures in an elongate laminar        support and arranged to provide backlit illumination for a        picture located in the frame,    -   the array being located in a tubular diffuser located in a light        transmitting tube, the diffuser having a diameter less than the        diameter of the tube, the tube being disposed axially of the        casing; and wherein control circuitry and a battery compartment        are enclosed by cover plates forming a channel to receive the        lighting means.

In a preferred embodiment the light transmitting tube is cylindrical andthe array is located in a tubular or cylindrical diffuser, the diffuserhaving a diameter less than the diameter of the tube so that thediffuser may be located within the tube, preferably resiliently deformedto be in contact with the inner surface of the tube.

Preferably, the lighting means extends actually longitudinally orlaterally of a rectangular or square frame, the reflector being disposedsymmetrically on either side of the axis so that the distance of thereflector from the plane occupied by the picture decreases withincreasing distance from the axis. In this way, illumination is suppliedto the lighting means in a substantially uniform manner across thelength and width of the cavity.

In a preferred embodiment, the reflector is supported by cover plates,each cover plate being located parallel to the axis of the lighting unitand inclined towards the lighting unit to define a trapezoidal or curvedchannel within which the elongate lighting unit is axially located. Thereflector serves to reflect light forwardly towards the picture and alsoserves to reflect heat emitted by the lighting unit away from theunderlying power supply and control circuitry at the rear of the casing.

In a preferred embodiment, the power supply is located behind the firstcover plate and the control circuitry is located behind the second coverplate.

The lighting means comprises linear arrays of light emitting diodes orother bulbs mounted in respective apertures in a laminar support.Preferably, the LEDs are mounted in straight line in apertures in anelongate insulating support. The support may comprise a narrow stripdimensioned to fit within the tube located across the length or width ofthe cavity of the frame. In a preferred embodiment, the laminar supporthas a multiplicity of axially arranged apertures, each apertureextending through a support to define a window to receive a respectiveLED unit.

In a preferred embodiment, the LED strip may be inserted into the tubeat any angular disposition without detrimentally affecting the evennessof illumination provided to a picture located in the frame. This affordsease of construction and assembly during manufacture.

A reflector may be provided behind the lighting means. The reflector maycomprise a metal sheet or film, preferably an aluminium sheet or a sheetof metallised paper or plastics material.

The diffuser and mounting tube may be secured at or adjacent each end byscrew clips or other convenient fastenings. In preferred embodiments theends of the tube and diffuser are open to allow dispersal of heat byconvection in use.

The power supply may comprise a battery or an array of batteries.Alternatively or in addition a connection to an external mains or lowvoltage AC or DC supply may be provided.

A light sensor or photosensitive detector may be arranged to interruptthe circuit during bright light conditions so that the display is onlyilluminated during dusk or night time conditions to avoid wastage of thepower supply.

In an alternative embodiment one or more outward facing surfaces of theframe or casing may incorporate or comprise a photovoltaic cell or anarray of cells. Such an arrangement is adapted to supplement or reducethe need for a battery or external power supply.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is further described by means of example but not in anylimitative sense with reference to the accompanying drawings, of which:

FIG. 1 is a perspective view of the device,

FIG. 2 shows the rear of the device,

FIG. 3 shows rotation of the fixing clips,

FIG. 4 is an exploded view showing assembly of the frame,

FIG. 5 shows the casing,

FIG. 6 is an exploded view of the casing,

FIG. 7 shows the control circuitry,

FIG. 8 shows the battery compartment,

FIG. 9 shows the sensor PCBA,

FIG. 10 shows the LED PCBA,

FIG. 11 shows a device including a solar panel,

FIG. 12 shows assembly of the light unit,

FIG. 13 shows the LED PCBA, and

FIG. 14 shows the circuit diagram of the device.

DETAILED DESCRIPTION OF THE INVENTION

The illuminated picture frame device shown in the drawings comprises aframe 1 composed of wood, plastics or other material. The frame may berectangular, square or otherwise shaped. An easel back 2 is attached toa rectangular casing 3 secured to the rear of the frame. The casing isremovably secured by rotatable clamps or clips 4 as shown in FIG. 3. Thecasing includes a box 5 adapted to receive a plurality of batteries 6,the box being closed by a removable door or cover 7.

The casing may include two attachments 28 for hanging the frame from awall by means of a hook or nail.

A light sensor 8, an on-off switch 9 and a DC power jack 10 are alsoprovided in the casing.

The mounting of the picture within the frame is shown in FIG. 4. Anacrylic or glass cover sheet 11 is placed into the rebate in the frameand the picture 12 is placed onto the sheet. The casing is closed bymeans of an acrylic sheet 13 secured to the forward opening of thecasing 3 by means of screws, clips or other fixings, and the casingassembly is secured in position by rotation of the clips 4. The casingforms a cavity to receive the lighting unit.

FIGS. 5 and 6 show the lighting assembly. A linear array of lightemitting diodes 15 mounted in respective apertures on a laminar strip orprinted circuit board 16. The strip is narrow and dimensioned to fitwithin a tubular diffuser 16. The strip is inserted into the tubulardiffuser 17. The strip may be inserted with the diffuser at anyconvenient angular disposition. The diffuser is preferably resilientlydeformed to be biased outwardly into contact with the inner surface ofthe tube. For example, the diffuser may be a spring fit within the tube.This serves to hold the diffuser in position during assembly and use ofthe frame. The diffuser is composed for example of opaque or translucentacrylic polymer or paper. The diffuser and lamp assembly is insertedinto an outer acrylic mounting tube 18 secured to the floor of thecasing by means of clips 19. Preferably the tube is disposed centrallyaxially of the casing. A reflective sheet or layer 35 is provided todirect radiation forwardly. The sheet may be composed of aluminium foil,other metallic materials or a metallised polymeric material, or paper.

In the illustrated embodiment, the lighting means extends longitudinallyof any rectangular frame. In alternative embodiments, the lighting meansmay extend vertically within a rectangular frame or longitudinally orlaterally within a square frame. The reflector 35 is disposedsymmetrically on either side of the lighting unit so that theillumination is axially symmetrically even within the frame. Thereflector extends from behind the lighting unit to a location against oradjacent the acrylic sheet 13 at the upper and lower edges of thereflector.

FIG. 7 illustrates the control circuitry of the device. A sensor PCBassembly (PCBA) is arranged to switch on the lamps when a signal fromthe light sensor indicates that the ambient light intensity has fallenbelow a predetermined value for example at dusk. The circuitry isenclosed by an inclined cover plate 27.

The battery compartment is shown in FIG. 8. The alkaline battery cellsor rechargeable batteries 22 are received in a conventional mannerbetween connector terminals and the assembly is enclosed by an inclinedcover plate 24 which may be secured by screws or other fastenings.

The two cover plates 24 and 27 form a channel to receive the lightingunit to enhance reflection of light forwards through the picture in use.The cover plates are preferably located parallel to the axis of thelighting unit and are inclined towards the lighting unit to define atrapezoidal or curved channel within which the elongate lighting unitand reflector are located. In this way the reflector may be curvedbehind the lighting unit to provide even illumination towards theacrylic sheet.

The PCB assembly is shown in FIG. 9. A transistor 25 and microprocessorare mounted on a circuit board by means of screws (not shown) orfastenings.

FIG. 10 shows the LED PCBA. The PCB 30 has a plurality for example fourapertures within which are mounted white LEDs 31 each LED having aresistor 32. The LEDs are disposed to emit light on both sides the PCBstrip, providing a robust and economical arrangement.

FIG. 11 shows an alternative embodiment. This includes a solar panel ofphotovoltaic cells 33 so that the batteries are recharged during brightlight conditions.

FIG. 12 shows assembly of the LED PCBA, diffuser and mounting tube,concentrically to form the lighting unit.

FIG. 13 shows front and side elevations of the LED array showing thatthe LEDs are disposed on each side of the PCB strip.

FIG. 14 is a circuit diagram. This shows the connection of thecomponents of the illuminated picture frame of this invention.

1. A display apparatus comprising a frame adapted to engage and supportthe edges of a picture, a casing defining a cavity disposed behind theplane occupied by the picture in use of the apparatus, lighting meanslocated in the cavity, a power source for the lighting means, whereinthe lighting means comprising a linear array of light emitting diodesmounted in respective apertures in an elongate laminar support andarranged to provide backlit illumination for a picture located in theframe, the array being located in a tubular diffuser located in a lighttransmitting tube, the diffuser having a diameter less than the diameterof the tube, the tube being disposed axially of the casing; and whereincontrol circuitry and a battery compartment are enclosed by cover platesforming a channel to receive the lighting means.
 2. Apparatus as claimedin claim 1, wherein a reflector is located behind the lighting means. 3.Apparatus as claimed in claim 1, comprising a light sensor orphotosensitive detector may be arranged to interrupt the circuit duringbright light conditions.
 4. Apparatus as claimed in claim 1, wherein theframe or casing includes an array of photovoltaic cells.
 5. (canceled)